From what I've read it's quite a hard one to get it spot on. I think I lucked out to some extent when I made it last year, the current one I'm not totally happy with either so already contemplating having another go.
What yeast did you use by the way? It could just be a combination of high mash temp and a strain that doesn't attenuate so much.
Fairly sure it was Bavarian lager yeast.